Warlock - All warlocks come with a stack of standard special rules - most notably being awesome.

Gunfighter - This model can use its ranged weapons even while in melee, but when it does so it can only target models it's in melee with. It can even make ranged attacks after charging.

Direct Spirits - When a friendly faction warrior model dies in this model's control area the soul may be given to any friendly faction soul taker in the control area. Also, enemies never gain soul tokens for things destroyed in this model's control area.

Zaal gains as many rage tokens as Skorne warrior models have been destroyed (and stayed destroyed). Any Skorne model can boost attack or damage by spending a rage token. Remove the unspent ones at end of turn.

Incorporeal - This model can walk through walls, terrain, models, and just about anything else. It can't be damaged except by magical effects. When it makes a melee or ranged attack it loses Incorporeal until its next maintainance phase.

Destruction Spawned - The Kovaas doesn't start in play - instead it appears when an Ancestral Guardian is destroyed. One in play at once. It keeps the Ancestral Guardian's souls and doesn't activate the turn it came into play.

Dessicator - Star action that places a medium sized cloud on the model. Other models that go into the cloud take a point of magical damage.

Soul Taker: Soul Cage - This model collects souls from living enemies who die near it. This model can store up to three souls and spend them for the following:

Soul-Powered - This model can spend souls to gain melee attacks during its activation.

Strength of Death - This model may spend soul tokens to boost attack or damage rolls.

Zaal1 is an infantry and ancestral guardian warlock whose main big trick is Last Stand, and whose secondary big trick is getting excellent use out of ancestral guardians. He also has a few tricks beyond that.

Scarab Pack - well done. You managed to buy infantry in your warbeast points(!) These critters synergize excellently with Last Stand. Move up all the critters to designated target. All of them have Last Stand; but you forfeit 3 out of 4 initial attacks. The last critter attacks. It attacks at 3d6 and damages at 3d6+11. It can buy all the additional attacks with fury, so you only lose a single critter to last stand. The rest are still there for future use, and you still produced 5 attacks averaging 21.5 damage pr. hit, without even considering boosts from the feat. And you can massively increase chance of paralysis by boosting some of the attacks.

His infantry is a much greater proportion of his force, and what he really likes is infantry that can get multiple attacks .

Ancestral Guardian - between Soul Converter and the Kovaas there's no reason to not bring as many as you own

Praetorian Ferox One of his two choices for assassins, Praetorian Ferox with Last Stand can frequently make short work of casters and have an excellent threat range.

Immortals With the Extoller Advocate, they can turn incorporeal, and then get a non-linear charge off with a total threat range of 14". Vengeance also lets them use two attacks in a turn for Last Stand.

Extoller Soulward Direct Spirits makes sure they have the perfect number of souls for blowing things up (two)

Gatorman Bokor & Bog Trog Swamp Shamblers With that many bodies, why not? Zaal can't use Faction spells on minions, but its an excellent infantry recycling machine for a warlock that likes to off his own guys. After you "Last Standed" your own unit into destruction, your Bokor picks up the bodies and reuses them the next turn. It can help Zaal apply pressure on the turns after the feat, if such a thing happens. It does not always work because opponents tend to have plans too, but its good fun. Apply Tough from a Paingiver Task Master, and get in the way of things like the best of them.

Without ancestral guardians Zaal loses access to his Kovaas. This means that literally the only theme force to suit him is The Exalted. He'd almost certainly love Masters of War if only he could take a couple of Ancestral Guardians and Hakaar in it but as he can't it's The Exalted or nothing.

It almost never happens but Soul Converter doesn't say it only applies to friendly Ancestral Guardians. So you can end up fueling your opponent's AGs in a Skorne-on-Skorne mirror match. (Normally a Zaal-on-Zaal one because Zaal 1 and Zaal 2 are the only casters who really like AGs).

The Ferox Assassination and the Immortal Assassination are both mentioned under their sections.

The Kovaas assassination involves leaving an Ancestral Guardian with Last Stand up. If it gets to Retaliatory Strike then the Kovaas pops out at the end of the turn. An incorporeal model fully loaded on souls that you can last stand and is right in the heart of the enemy army? Throw last stand on that and it tends to demolish casters.

Models with Combined Melee attack love Last Stand. Only the model that initiates the attack gets destroyed!

Remember, if the enemy caster gets too close you can Last Stand Zaal himself and beat the enemy to death. If the enemy caster dies first, Zaal wins!

Did we mention how awesome Last Stand is?

His gun is really good against gargantuans, being +1 or +2 against most. Whether you want to be that close to one is up to you...

The minion warbeasts you can include in a Skorne army depends entirely on what type of model is commanding them. There are too many permutations to list here, please refer to one of the model entries above for full details of what it can take.